Biomedical implants, such as hip replacement joints and orthopedic implants, have been beneficial to patients with degenerative disease and patients suffering from disabling injuries. Implant surgeries are often very costly and painful, and result in a long recovery period. Many patients with implants are often required to undergo at least one additional surgery, called a revision surgery, after a period of time. Revision surgeries are often necessary when the existing implant, after time, fails to perform its function properly and/or causes pain to the patient. For example, some orthopedic implants, such as hip implants, loosen from the bone after 10 to 15 years and require replacement. Patients with failed implants such as these are often elderly and in a weakened physical state, which can augment the risks associated with major surgery.
One of the main causes of low implant longevity is a poor implant-to-bone bonding, or interfacial strength. Implants made of materials which do not sufficiently accommodate bone cell growth can form a weak implant-bone interface. Research and development efforts have resulted in some improvement in this area. For example, there have been improvements in implant coatings and non-controlled porous surface modification.
Sintering is a method that can be utilized to create pores on the surface of an implantable material. U.S. Pat. No. 7,635,447 discloses a method of providing a porous metal implant by sintering mixtures. U.S. Pat. No. 4,547,327 discloses a method of providing a porous oral prosthesis by means of sintering polymeric particles. U.S. Pat. No. 4,179,485 discloses a method of providing a porous aluminum implant wherein grains of alumina are subjected to firing, compression, and sintering.
Laser etching and plasma gas surface etching have also been used to create pores. U.S. Pat. No. 7,018,418 discloses a method of creating micro-recesses on the surface of an implant by means of laser etching. U.S. Pat. No. 5,843,289 discloses a method of creating surface porosity by means of plasma gas etching.
However, such methods, which involve the creation of pores in an uncontrolled fashion, have failed to adequately meet the need in the art to provide biomedical implants made of implantable material which demonstrate improved longevity and durability and can improve the quality of life and reduce medical costs.
The biomedical implantable material of the present invention meets the unmet need in the art by providing a material which enhances bonding between a bone and an implant.